Purchase Order - Extra confirmation choosing problem

Hi friends,

I have two confirmation keys and I can choose only one confirmation key in a me22n screen.

How can i choose confirmation in a lot of keys.

ME22N:

Step 1: First I choose "teyitler"

Step2: Second I choose "teyitler2" and I Got error after press "Enter".

And Then, I cant change confirmation. It was hide.

Thank you very much